1. Technical Field
The present invention relates to a liquid body discharge device and a method for discharging a liquid body.
2. Related Art
There have been liquid body discharge devices that discharge liquid bodies such as functional liquids and ink to substrates made of glass, ceramic, resin, or silicon to form (also referred to as “draw”) predetermined patterns (also referred to as “drawing patterns”). One of such devices includes a head in which a discharge mechanism and a circuit substrate to control the discharge mechanism are built. The discharge mechanism discharges a liquid body by applying a pressure to the liquid body in a pressure chamber provided in a middle of a flow path through which the liquid flows by using an electrostrictive property of a piezoelectric element or thermal energy. The liquid body is discharged from a nozzle that is provided to the head and located at the end of the flow path. Typically, a plurality of nozzles are formed as a nozzle group. The nozzles are aligned in a substantially straight line as an alignment direction with a predetermined nozzle distance (pitch).
When color filters are formed on a substrate by drawing patterns using such a liquid body discharge device, there is a case where the drawing patterns of drawing regions of color pixels, i.e., liquid body discharged regions to which color liquid bodies of R (red), G (green), and B (blue) are discharged, are different depending on the color filters. When a plurality of color filters corresponding to different display sizes from one another are formed on a single substrate, the color filters may have different drawing patterns. For example, the color pixels corresponding to R, G, and B each having a rectangular shape with a longitudinal side are employed, the longitudinal direction of the color pixel included in one drawing pattern is orthogonal to the longitudinal direction of the color pixel included in another drawing pattern. In this regard, a pixel pitch between the color pixels adjacent to each other in the longitudinal direction of the pixel is different from that in a direction orthogonal to the longitudinal direction, i.e., the pitch in the direction orthogonal to the longitudinal direction is shorter than that in the longitudinal direction. In this case, when the color pixels are formed in the plurality of color filters by discharging respective color liquids from nozzles formed in the heads so as to be aligned in predetermined alignment directions, the following problem may occur. If the alignment direction of the nozzles is substantially in parallel with the longitudinal direction of each color pixel, each color pixel can be formed. In contrast, if the alignment direction of the nozzles is substantially orthogonal to the longitudinal direction of each color pixel, some pixels are not formed because the pixel pitch is shorter in the alignment direction of the nozzles.
To cope with such a problem, the alignment direction of the nozzles needs to be optimized in a direction based on each drawing pattern. For example, JP-A-2002-273868 discloses a technique in which an alignment direction of nozzles (a nozzle group) is rotated to an angle suitable for the pixel pitch of each color pixel to draw patterns.
However, when the alignment direction of the nozzles is rotated as described above, the head needs to be provided with a rotating mechanism to rotate the nozzle group. Therefore, the head becomes heavy due to the weight of the mechanism, resulting in a problem in that the head is not easy to be replaced. In addition, another problem arises in that the position of the nozzle group after being rotated is varied due to uneven rotations or backlashes occur in no small part of rotating mechanisms, resulting in the liquid bodies being not discharged at desired positions.